Elizabeth on Vast.ai — Architecture, Status, and Next Steps
Why (Rationale)
- Local serving for latency, privacy, and control (no managed endpoint dependency).
- Repeatable, fast launches via container images and Vast templates.
- Clear separation of concerns: serving (vLLM), training (accelerate/deepspeed), and observability.
- Reproducibility: pinned Docker tags + pinned model revisions (HF or Volume).
High‑Level Architecture
- Serve (inference):
- vLLM on GPU; OpenAI API on :8000; API key required.
- SSH + Jupyter for interactive ops; can be disabled in hardened prod.
- Uses local model path (prefer Vast Volume) or HF pull on first boot.
- Train (finetune/resume):
- Dedicated container (accelerate/deepspeed/bitsandbytes).
- Writes checkpoints to a separate path; never overwrites serving weights.
- Promotion flow to update serving safely.
- State/logs:
- Sessions: DragonFly/Redis (fast) + Postgres (durable).
- Logs/DB snapshots consolidated under /data/adaptai/projects/elizabeth (cron ready).
Images & Bases
- Base for “-vast” line: vastai/pytorch:@vastai-automatic-tag (CUDA 12.6; SSH/Jupyter/portal included).
- Serve image (planned): elizabeth-serve-vast — adds vLLM + CLIs; starts SSH/Jupyter/vLLM.
- Train image (planned): elizabeth-train-vast — adds training stack + CLIs; starts SSH/Jupyter.
- CUDA images (existing): elizabeth-serve, elizabeth-train (CUDA 12.6, SSH/Jupyter added).
Data Layout
- Canonical: /data/{models,ckpts,logs,cache}.
- Symlinks: /workspace/{models,ckpts,logs,cache} -> /data/{…}.
- MODEL_PATH default: /data/models/qwen3-8b-elizabeth-sft.
Secrets & Auth
- Vast User Env Vars: HF_TOKEN, GITHUB_TOKEN, VAST_API_KEY, DOCKERHUB_TOKEN.
- Entry auto‑auths CLIs if tokens set; no secrets in images.
- vLLM API uses a bearer key; HF pull only if explicitly enabled.
Model Source Strategy
- Short term: HF pull (pinned revision) into instance disk.
- Medium/long: Vast Volume seeded with weights → mount into serving container (WAN‑free restarts).
CI/CD
- GitHub Actions builds/pushes images to Docker Hub (adaptchase) and GHCR (adaptnova).
- Matrix builds (serve/train); tags: latest, short SHA, optional release.
- Build time tracking: add run Summary + CSV artifact (TODO below).
Vast Templates
- Serve template: image elizabeth-serve(-vast):latest; ports 22/8888/8000; portal links vLLM.
- Train template: image elizabeth-train(-vast):latest; ports 22/8888; MODEL_PATH/OUTPUT_DIR envs.
Promotion Flow
- Train → checkpoint under /data/ckpts/elizabeth/checkpoint-XXXX.
- Validate → promote into /data/models/qwen3-8b-elizabeth-sft (or use scripts/promote_checkpoint.sh).
- Restart serving → verify /health + sample completion.
- Optional: publish promoted checkpoint to HF.
Logging & Auditing
- Logs centralized: /data/adaptai/projects/elizabeth/logs (indexed).
- DB consolidation: inventory + archive DB under /data/adaptai/projects/elizabeth/state.
- Optional Redis snapshots (eliz:* → JSONL).
Security
- vLLM API key; SSH/Jupyter tokens mandatory on public IPs.
- No secrets in images; env only; consider IP allowlists.
DR
- HF repo with pinned revisions; Docker tags/SHAs enable rollbacks.
- Optional S3/GCS for large optimizer states.
What’s Done
- Local vLLM serving on canonical path; curl tests OK.
- Session logging: Redis/DragonFly + Postgres (CLI + orchestrator wired).
- Logs/DB consolidation + cron wrapper.
- CUDA 12.6 images for serve/train published; SSH working; Jupyter when mapped.
- CI to Docker Hub + GHCR; Vast templates created; base flow validated.
In‑Flight
- Bake “-vast” images FROM vastai/pytorch (serve/train): user x, CLIs, symlinks, SSH/Jupyter/vLLM.
- CI build time tracking (run Summary + artifact).
- New Vast templates referencing “-vast” images.
- Launch on 4× H200 (DC 135125, machine 32376) for SSH/Jupyter/vLLM verification.
Next (Near‑Term TODOs)
- Complete build & push of elizabeth-serve-vast / elizabeth-train-vast.
- Register new Vast templates; record IDs.
- Launch on machine 32376; verify SSH/Jupyter(:8888)/vLLM(:8000)/portal.
- Add CI step writing build durations (serve/train) to Summary; upload CSV artifact.
- Decide HF pull vs Volume for prod nodes; seed Volume if chosen.
- Harden prod templates (optional: disable SSH/Jupyter by default).
- Document rollback (pinned tag + model revision).
Future (Mid‑Term)
- Promotion guardrails (smoke evals) before swap.
- Multi‑node scale‑out via templates + pinned tags.
- Optional ClickHouse export from Postgres.
- Derived images for hardware variants.
- Syncthing for small artifacts only (not weights/checkpoints).
Runbooks (Quick)
- Health: curl -sS http://:8000/health
- Completion: curl -sS -H 'Authorization: Bearer ' -H 'Content-Type: application/json' -d '{"model":"qwen3-8b-elizabeth","prompt":"Hello","max_tokens":16}' http://:8000/v1/completions
- Logs index: /data/adaptai/projects/elizabeth/logs/INDEX.md
- DB inventory: /data/adaptai/projects/elizabeth/state/DB_INVENTORY.md
- Maintenance: /data/adaptai/projects/elizabeth/maintenance.sh